1. Field of the Invention
This invention relates broadly to an improved scraper system for cleaning conveyor belts. More specifically, this invention relates to an improved scraper system embodying resilient tapered blades held and flexed by air cylinders against a moving conveyor belt as it passes around a head pulley of a conveyor belt installation to remove muck and very wet material from the conveyor belt.
2. Description of the Prior Art
Conveyor belt cleaning systems have long been known and used.
Thus, U.S. Pat. No. 3,047,133 (1962) to Searles shows a plurality of pairs of resilient discs held together by backing discs of smaller diameter, which resilient discs are mounted for rotation on a shaft and which are so urged towards engagement with the conveyor belt that the said resilient discs spread apart from each other beyond the diameters of their respective backing discs, thus presenting rotating circular segments to the face of the conveyor belt and thereby effecting the desired cleaning action. This design, while good for cleaning granulated gritty substances from the conveyor belt, has not proven to be totally satisfactory for removing muck and very wet materials from the conveyor belt.
Scrapers are also commonly used to clean conveyor belts, but are blunt and not tapered where they engage the belts. When in operation against a moving conveyor belt from which material is to be removed, the material has a tendency to chew out or erode the leading edges of the scrapers forming pockets between the scrapers and the conveyor belt, and to remain in the pockets, causing a smear action and carry-back, thus reducing cleaning efficiency.
Various mechanical means, such as ratchet mechanisms, threaded mountings, springs and counterweights have been employed to hold the above mentioned scrapers against the moving conveyor belt, but none provides for constant adjustment of scraper position at a substantially fixed degree of flexing across the entire width of the moving conveyor belt whereby the entire surface of the belt is scraped clean despite wear on the scrapers and unevenness or other on-uniformity of the belt or of the head pulley under the belt.